SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '43f009e03465f517a19ca424cee7146969c96ca16f7471798ad02331b4029ea1' 
  AND token = 'ZYg/fBPSOvD4ZI3ECZEjk2LMhfAqowoupmdSH27Y6u0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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