SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd3c65f7acecfcc0692d0a2e32fe699dc01ef378554906399690465f158ce97c5' 
  AND token = 'aDWm7jM054KoGpD0NprvPnrXip8duNPoZXdxzXGQILY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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