SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2ba8337b42c39817585c5c9e64f9c2e67c15899c15154015658ebc31f0b2ab0f' 
  AND token = 'JNi5T84p9YxzcT1dotnEZJwzCQRchPCQ12ugORFmrM8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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