SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'd704f521549b92cbe008fe7f129c4e32baecd2434c2fafbf98986e58d139bbc0' 
  AND token = 'Qk1qbaITbxIBaYDWy0E/0w0oKJb+xki5PhWTFEsQ16E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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