SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1e0c0367618c72f2e79140462543215fd8dba7443e3258e458e4556601ecc153' 
  AND token = 'xzBa5ylW3toNhGGbt+YhSucbG0TSr/w3K07k6THDtCw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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