SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4557e7276e2e02e2d7602900ee85310aca07bdbbd13aac9e2be91c6d7a8cdfeb' 
  AND token = '+JyKX55SBrnv/rUn6mck318rR/DvPOWOfgHF0X29JwY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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