SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '03c551bbe9961dc24db332aad7f3909893a41a37f127dabb913cd02a765e3f10' 
  AND token = 'VR93SCn5ihBzhyz5pWlnyh3LPOPTOb1d2xo7qbNjmgE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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