SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1f0d53a40bbe01c886e0f359ab0f0bc9bcffbc9b97959b19c0a421e7354fe2c8' 
  AND token = 'KL5XsJmzHouYsXfBBUxMPFjqWibn2+KpuOLS0YeyniQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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