SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bf574012bd910584c2765885cba35401545cffab01cad0b28c66534067d5837f' 
  AND token = 'CEhzlo0+BA8cQzQsYPTDhphqGB8UwL9sYcxoqVLZCts=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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