SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '429bd207bbddb41d1a1395cb95018738aa99029574ade3910c58b83ee97b92ab' 
  AND token = 'bI89br4Gij8KYPrM58/O27gE4i0yxMYRt9qnHdXMGDc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}