SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cbd205075bf7e687d2239edab03c5618d63ffb03e7875924534bff7db3aa3700' 
  AND token = 'JHTkQoqhR/GGCueQTMpNZBzYZyqNGtw+FeauLlyV2ng=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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