SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '28c12de470a90ef6346cd7441a359db407b3194bfbd642468801efd0bd8f3e52' 
  AND token = 'TIb+7q+DMDCjvfWdXtedo+x3SQqsKgjXxOZH/VRFAAY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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