SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc8abef668079152ef320e32fab498288b953b2c401f351fa59a11c8c2f2c85f' 
  AND token = 'f1yI4o2xbwlgAoHIhbCVNGgjxRXBEHvkPCAtAI6Kidc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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