SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2255a8664b224404928afdd2ab6760ca365e2574ea5b0a329ec3fa1b7378cfdc' 
  AND token = 'WrRiNs5vBqx0E5R4Oznb26T7LRDTAgfPRIh83KXbJh4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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