SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2428286ae405274933afff972ddfbd607611146097945ffaa608e0d464f496a8' 
  AND token = 'DLJhrv/JMbmMwnLTLbS4NPW8UJ+4q2x38wLc6+q8jvs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}