SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9e5f0638b5fa9f71520cc9f292d632dd76742d8906d686ba0f291c026508588b' 
  AND token = 'Huhw/E8CPwB/HfpOtX56Kl0+Y38kJ9gMRmRmff3Tqtk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00008

JSON explain

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