SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '40e8b794f65fb59a3889c58e11df0a1141adab479c1da6525f8d1e20f146d91e' 
  AND token = 'yML/VElkWeczvL9SASeEVgAHMon0QSEitlOkkUSM7Lo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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