SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1c86261f0b35826cc06c1044c29d93ad084b825bc4b2376591b949982922e52a' 
  AND token = 'Yhi1uLBdqqxwBseUxWEd6zb3FdBMh8m6ls9CcxllfDc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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