SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '19f6f26673992e44fdbb5ac21ca88007afc94b8b35bb9541346d4447da773979' 
  AND token = 'NwJqmMOauUVatEUrcVozHFRO4BxhsY2h4SYmMLLqVgc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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