SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4a0697ed0f27b436c41a92f25667db5957b8a9e79e73e9aae1ebab07d0ad1fa1' 
  AND token = 'T+KmmkbOmDdEDCwRvgl60ZfhriNPUOwDzUxLDCWmtC0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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