SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4484076fe962ffcc6f0d072f82383fbc1a9f8cdae12d5add40c1ca4b8b428c1d' 
  AND token = 'qVbE6uMbGSbcgABqvMTG1zT3tFU+TKt5u6vi83LxSR0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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