SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0a76f72766029d62550ff716e2074ebf2fe38eff95cbb01780d80ca3c90255cd' 
  AND token = 'o5x61H5RHpGNRTCOeSKjr4yc87VkHhOuZWiFyijKpsY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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