SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '70c473d37c025621f8521574c030703e4ccabf2b9859dfcce3f8f151eab2de60' 
  AND token = 'RDF1OU3+RYBzKREp8DiYvhQNdVkpAYJDPBB6G9HAWE4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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