SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3f1136d8bc8272f97318735a5f8c956d5b8c163e7ca66144e42923e1fbf1332c' 
  AND token = 'zE5pEzFrgsgCouaw8y9qEGT3BzLkQ+sw2/Fe++vp+xc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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