SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dd01ff2d7108e4fcf38a933b7bdcf5224ad2a0643ef3ecb25868b50ac279f818' 
  AND token = 'OzKjzi/oRWFVBxtG65i4vGNZJhy5nrl9ieFMUEZz1/c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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