SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '95e5d1687184298202ef310be950951a58b907eb761c3d1575bd9b3e245af97c' 
  AND token = 'ichGIfcvVLuUB1oXhqaQ1AqACFBpgFdWhm3mQm4u47o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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