SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e2d63accb563cb86be0de3f9f4c5603dfb0a05f0a2dad6d00d5388d1ae25bd25' 
  AND token = 't5KaY5esPAQDpPC+GAgfSqJXparSS4U5hJgz7olk6Ic=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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