SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '674009504d0cfa164ce5453e9e79d90c90511115e1745fcae03f3099488b0e3c' 
  AND token = 'xFEQ8dZGelXSV2z8A6vA1vWSPDPU0dXecsmxpfuErwA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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