SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a00af8cd927faf55678f07f574592c834e3183379b152932ce37efccfea2f36e' 
  AND token = '1xvqv6kFNmg+6UsJZmcnM12O5tvQuqW/Nz+dpKKq7PU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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