SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd16e5a503acabf932add1bc860fea78df12102bf2453461e5874465d6377ef67' 
  AND token = 'Uqzd4goRAi/VSgmdWw9YY7j8QNGLg5BUtUl7bPCyo54=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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