SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '87e5628cb286b2abfd6113181939834cb58b7b25942f064e66869638ca113ef8' 
  AND token = '/5yuPXEdAlO+M5OcrnreEkmoBfnlW1gViHvsFyatWAo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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