SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '54cd7bd8b2944623f920bda7b0d0d41e22d8108e990fc92dacc5ded6e4566a0b' 
  AND token = 'KMCQi7YWjsYQXUwqVhgaa/Qe9V3BKVVI/EVwN/HjprI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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