SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'becc025c13a618b011088997e276456866ba302088f986a7b6091e410c1d71d9' 
  AND token = 'qgdf6pnSssr0fswbcrFzi5cvt8r7ZZqKuR0tMO1rwC4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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