SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b08f2ce62acd1788c4ad1863885f461929a2cfe7a71e3dbc419543b10cd6c02b' 
  AND token = 'Rv1BWVuk2jWHjTyYQs/J341UsUOHhCyJfvSXHYNEsgc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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