SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9b6dfb7097d5083563f94b9cb69f5430e24317ae59a52f88eb2366b9db938a19' 
  AND token = '2xJbxF6Q8kryaHjDTecwQK5VhWYBo4L7IcK1DKEPacQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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