SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '89a34c009d52050e2c47e13f8882b002cd17515688a0d100edfbd62582641a51' 
  AND token = 'faNPYC02mwq61vftOwj7X7yA9qkUzJIKLB/B39g/kO4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00057

JSON explain

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