SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ee0a60f31ab38a572fca26c9840ceb014031560212acc554ac6112cfd075e3d8' 
  AND token = 'eUgXZCiTcoiAt8s1hjE6Y++lHwuxiZ6t5qOp057uZEg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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