SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '77da06a55ff2a1215791d75250928eb46c44aeb395cfa75236b700086f296122' 
  AND token = 'Q0kqNU3PSpgy2ZBs0Tjh+Nbwe4i4VBUeSigD46WrYZM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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