SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ec7a3d14b40a5caafaa8e8cc92742ecc232ce827e5f47d62b32f0b9120a96e35' 
  AND token = 'RFqQxrqPpicTX2OFhUtX7XM2hFeiLNd8dfHw2sPE+6w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}