SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e31db03898e246d035236a3158f1e4f3119e41134471ba9da3dede0ef07ded77' 
  AND token = 'aE2Epp1yGIAk65eIqN9N57/Z8Gurmp17TOKQIVP8w2w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}