SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2db353bfc396c659537d813bdd656ac2a877c36916adf30097cab956f50eb0fd' 
  AND token = '+ODYeGeIJ3j3ZfTeGwYNAtZ1fo3pofGsOoct4pQjbxY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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