SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '270837dc146cd19a83f5471b6761364c53724e6b5f9b78ec0e8388d1beda7cb0' 
  AND token = 'kqCFTQRKc6oed9MEsquKuBGfUk+HO2P4QtyPzrjEssE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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