SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '886a13c1a59fea27b53dc481ad0fd227eaa58578f34725da8ffe0b2bab948974' 
  AND token = 'vm+iYmemxEQSutpztqAs0BDh0yL5Oo0tw1KrVhXwfCE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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