SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5634771e78b1cc4647935b3df36c326d1b231397d689ec5c57fa20b7c1ecfc5a' 
  AND token = 'GETZuxjJDXR1aCzQgpsERuidyOkMxywrvFjBXXqR5KU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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