SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '12c1ee2131f59a034fc982915639b22d55522aba0b1765a05f71b1c0d7000329' 
  AND token = 'A4UclKqA/mhPPv6n+ndZVMrD6mJOvQ4DHx/F+bmK7hA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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