SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e3286c826bdba26fdb41b61726990da20c4e794a5ba5b58d90637b4b7a2a7582' 
  AND token = 'UVP9lcPqakC3/oAmFUNJEAFSmLtm2TBIePk7S72ApdE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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