SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd9a0f3e6b36f849506eef0462e372cebeeff1927685ccc20d2d62a7651caeb3a' 
  AND token = 'i1Ybv1CN6mxT1cRCSG+b/OUUNYO9/v+mYEJ7ZvFxg2k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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