SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '740801ab95f2106adaa59f6c1f03ea86c64cc4864fb94c3c9ae6e8654dbca5f0' 
  AND token = '4I7ixjRHEAIBEHegtjFayAcc3L2OXIUxwBaeVaYl1+w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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