SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '428f70ce44c1afe8e3222eadf2f5bfc121ae102c0e2f9717278962bcddafd14b' 
  AND token = 'kYH4dPRWmfx7i/juITaqHRtM4HyKHUHSH2KRo1grgPg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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