SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bced07e1cc9ac2205db9d0b1263b850e9f624d08e099bf0e43f743cd94341666' 
  AND token = '9j2HQqzTyEjmryhHgZ0BS1Ge70mmTldIttTYf/LTG2k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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