SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6bd5c5d94dfda4d44e10cc6ee33e1ba0f924aa99c09c6bdc4f3cd815cbe682de' 
  AND token = 'srdylouoRHDvC9zQKcUV0xsL51esTbORLCEufJKSYp0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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