SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '49f20379f826de44a9de5855608c2de1259c3167ffb50d773d793afd7a706cf2' 
  AND token = 'ty1lpPIDuCWqso0TZ+KgcbboqEYlhbN2sQNbWEM1SLs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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