SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fc15d02610c94dc86c47ea5ca42f19e0df5684a7be9e8fd4fa144e15961db11e' 
  AND token = 'qzg2lvFOxV/HJhFPMPv6mpn/NDvIbnpifCOJD+3Vcbo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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