SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c845c0a3a8ae1f07d3940421a08aaede4cb85dd9091e5d66cbe000b1b106648a' 
  AND token = 'EU/qBp//5+b8VX/74EcQzr+MyD9lpAykJoNpDgN+s14=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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