SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '58674376d65641256bb7aa3ee1a41cec3738bcbcae2258469b658f62a78e1a54' 
  AND token = 'd3TCZCyyTnB/ISqdpQKLBaHYIgVFwSkDFk7xFet0qjE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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