SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1984d0ec39877d40010937c64ee55da830df59bdf4558fd219843468cbd353b0' 
  AND token = 'VEdn4mN5lEOYOGyd+qno4jnrksYAQMcaIV1DJWZkssA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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