SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2d4e0004b516093cefd514123084b75e4fb5281f87a21201991431d91b8abd71' 
  AND token = 'cIIQuSCZF2tgaC9xDGk051q14B11O0ir6CT3pgsmxzs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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