SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bde0b6b019153453419fcf9782780ad969865e00394b5457618fa12cd94248eb' 
  AND token = 'pgtSUKg3dXK4MRhi7jxf3/bFhgWGEFR4TqBCeIrEM+s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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