SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '42eb3a4598becd548d09e248f41f90d930e4440a4874e807c5c633f678a00b2b' 
  AND token = 'pC8l7FbqBae978WKpJKKCR0wZdJGuRuGNrVMd0eQO1w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00060

JSON explain

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