SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6152a6cd70d692b848ca4fcb3911ee8cd056c5ec549dc2342c9e517a8c61575f' 
  AND token = 'zyKhM82LpGMP+YeFA9N1ozQUqUT8QP6JTuLwd1QvyjY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}