SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a869a490f5f369cb5b3fdb4c184c9ca870a12b540844fc30bbe997f4a4ac81b0' 
  AND token = 'ByomVHsjD4CGJNUf3cvEHoySm0PEQPGNPyd16kPMuS0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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