SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ed329cacd7cbd8571a944055ff8525e1a5d5232ebb3819b5b7b6e43a710463d2' 
  AND token = 'nhtNwMM6f5fuPdBJiLnPtWnnQwLzLNA1sWwThmsFTmM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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