SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '98838aa57da79c9c703ab5153e7180aaf01085f01c6e982482ee16bbe0c7d090' 
  AND token = 'Bn9drBNoDDj9aDj95w/+71Feh0VOfccLEeJ477RZDQU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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