SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f3aaaa5bac7d85a2d4f443b769375955387cc724e1b7698415c1e87543adc691' 
  AND token = 'F5aeBV2GGykibk2ezhEwdaKfP6lq8kNopAFtYG7j6Cw=' 
  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"
    }
  }
}