SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5da677115a7c2ac9284d957cb36f2ec2eb3120bed9fe922b0ba734b119e723bd' 
  AND token = 'EI8DLT/fHpazDkRZyOitfBXft6hQsyNvzyJUnAIf83Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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