SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'dec0851ffd307aacd85d6025cb98deb1023813164418ded4943c273449688c7f' 
  AND token = 'P/RulIs0vJ9QHo0z3kbFSZmEtEVGjHRZGedyGK1sdis=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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