SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cf07b2a2806afdea82b07002edafd791d49e8814e43395737db6deb0df73c98a' 
  AND token = 'BG5B+Pry1tMvc1R1/GQJ16Y3snZ4mvzsygYmqi+QfDM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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