SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6d67cc93a7705a2090a03c07d60eee9533d84a7f7ca9fe0d542b660fdc0920b3' 
  AND token = '90IeOIiz752uwwfdASXow2yrsWUXBhHT7Vlhlb1iIUI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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